Cobalt(II) chloride complexes with some phosphine oxides: compatibility between structural data for the solid complexes and their stability constants in acetone medium

Binary complexes of general formula CoCl2L2, where L = triphenylphosphine oxide (TPPO), benzyldiphenylphosphine oxide (BDPPO), dibenzylphenylphosphine oxide (DBPPO) and tribenzylphosphine oxide (TBPO) were considered concerning X-ray structural data for the complexes in the solid state and their stability constants in acetone solution. Compatibility between structural data and stability constants are pointed out. Previous investigations showed that in acetone medium, with CoCl2 as reference acceptor, the following basicity order is obeyed: TBPO > DBPPO > BDPPO > TPPO. This sequence is supported by X-ray diffraction data of the solid complexes and by electrolytic conductance values for these complexes both in acetone and in nitromethane media.

Effect of deforestation on water chemistry in the Kościeliska Valley in the Western Tatras in southern Poland

Effect of deforestation on water chemistry in the Kościeliska Valley in the Western Tatras in southern Poland. Bark beetle infestation is a leading source of local tree stand damage in Tatra National Park. In addition, hurricane-force winds also cause damage to tree stands, as in the case of the 2013 wind event in the Kopki Kościeliskie area of the Kościeliska Valley. The purpose of the study was to determine the effect of deforestation on seasonal changes in water chemistry, especially in the case of nitrate. The research was performed in the years 2015 and 2016 in seven catchments. The total number of monthly water samples was 175. Three forested catchments were selected along with two catchments deforested by high winds, one catchment deforested due to the action of the bark beetle, and one catchment affected by several different forms of deforestation. The following four types of measurements were performed in the field: pH, electrolytic conductance (EC25°C), total mineralization (Mt). The following analyses were performed in the laboratory using DIONEX 2000 ion chromatography equipment – concentration of 14 ions in water samples: Ca2+, Mg2+, Na+, K+, NH4+, Li+, HCO3−, SO42−, Cl−, NO2−, NO3−, PO43−, Br−, F−. The concentration of NO3− was many times higher in samples collected in deforested areas (x̅ = 16.53 mg·L−1) versus forested areas (x̅ = 3.06 mg·L−1). The share of NO3− in overall water chemistry in catchments deforested by high wind events is more than three times higher (3.25% mval·L−1) than in forested catchments (1.07% mval·L−1), and almost twice as high as that for a catchment affected by the bark beetle (1.8% mval·L−1). In fact, it is high enough that the position of the nitrate ion in the sequence of anions in the deforested catchment shifts from HCO3 > SO4 > NO3 > Cl (natural sequence occurring in forested carbonate-type catchments) to HCO3 > NO3 > SO4 > Cl. In addition, the concentration of nitrate in stream water was found to be lower during the vegetation season, which is associated with the nitrogen intake of plant root systems in the summer season.

Synthesis, characterization and fungicidal activity of some diorganotin(IV) with 2-thioacetic-5-phenyl-1,3,4-oxadiazole

Complexes of the type R2SnL2, where R = phenyl, butyl and methyl and LH = 2-thioacetic-5-phenyl-1,3,4-oxadiazole, have been synthesized and characterized by physico-chemical (elemental analysis, and electrolytic conductance) and spectral (UV-Visible, IR and (1H, 13C and 119Sn NMR) techniques. Monomer structures for the complexes, bidentate and octahedral geometry was proposed for the complexes prepared. Preliminary in vitro tests for fungicidal activity show that all prepared compounds display good activity to Gibberela, Cercospora arachidicola, Physolospora piricola and Fusarium oxysporum. Moreover, the Ph2SnL2 shows a higher inhibition percentage then diorganotin carboxylate.

Synthesis, Characterization, Spectral Studies and Antifungal Activity of Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) Complexes with 2-(4- Sulphophenylazo)-1,8-Dihydroxy-3,6-Napthalene Disulphonic Acid Trisodium Salt

Complexes of the type Na6[M(HL)2(H2O)2], where M= Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) and Na3H2L= 2-(4-sulphophenylazo)-1,8-dihydroxy 3,6 naphthalene disulphonic acid trisodium salt, have been synthesized and characterized by physico-chemical (elemental analyses, solubility, electrolytic conductance, magnetic susceptibility measurement) and spectral (UV-Visible, IR, ESR, powder x-ray diffraction) techniques for their structure and studied for their antifungal activity against ten fungi. The anionic 1:2 metal:ligand complexes show octahedral geometry around M(II), a significant antifungal activity againstCurvularia lunataandAlternaria triticinaand a moderate activity againstAlternaria brassicicola,Alternaria brassicae,Alternaria solanae,Curvularia species,Helminthosporium oryzae,Collectotrichum capsici,Aspergillus niger,Aspergillus flavusandFusarium udum.